Calculate the charge on mercurous ion and its magnetic moment. `EMF` of the cell given below is `0.0295V` at `25^(@)C`.
`Pt, Hg(l)|{:(0.01 M mercurous),(nitrate solution),(i n 0.1 M HNO_(3)):}||{:(0.1 M mercurous),(nitrate solution i n),(0.1 M HNO_(3)):}|Hg(l),Pt`

Explanation

The given cell is an electrolytic concentration cell.
`E_(cell)=E^(c-)._(cell)-(0.059)/(n_(cell))log([C]_(anode))/([C]_(cathode))`
`=0-(0.059)/(n_(cell))log.(0.01)/(0.1)`
`n_(cell)=0-(0.059)/(0.0295)=2`
Thus, charge on mercurous ion `(Hg_(2)^(2+))` is `2.Hg_(2)^(2+)` exists as `Hg^(o+)-Hg^(o+)` and its magnetic moment is zero since there is no unpaired electron present in it.